Vehicle steering mechanism

ABSTRACT

A vehicle steering mechanism which includes separate transversely movable steering members linked to each pair of wheels of the vehicle for individually turning the pairs of wheels about substantially vertical axes in accordance with the transverse movements of the steering members relative to the vehicle. A motion translating device usable in a linkage of a steering mechanism connecting a steering member to its associated pair of wheels which is selectively adjustable to cause the pair of wheels to turn in either selected one of two opposite directions upon transverse movement of the steering member in a given direction relative to the vehicle to provide for proper steering of the vehicle regardless of which end of the vehicle is the front end in the direction of movement of the vehicle.

Jan. 7, 1975 VEHICLE STEERING MECHANISM Primary Examiner-David SchonbergAssistant Examiner-John A. Pekar 75 l t H C.Alls F tW h, 1 men or gi Jror Attorney, Agent, or Firm-Walter J. Jagmm; James M.

Cate [73] Assignee: LTV Aerospace Corporation, Dallas,

{57 ABSTRACT [22] Filed: 1973 A vehicle steering mechanism whichincludes separate [21] APPL 346,562 transversely movable steeringmembers linked to each pair of wheels of the vehicle for individuallyturning the pairs of wheels about substantially vertical axes in UsS- CLr accordance the transverse movements of the Int. Cl B6" 9/00 Steeringmembers m to the which A motion [58] Field of Search 180/79; 280/872;translating device usable in a linkage f a Steering 104/2441 247; 46/244216 mechanism connecting a steering member to its associated pair ofwheels which is selectively adjustable to [56] References Clted causethe pair of wheels to turn in either selected one UNlTED STATES PATENTSof two opposite directions upon transverse movement 3,338,182 8/1967Maestrelli 104/247 Of the Steering member in a given direction relativeto 3,724,584 4/1973 Varichon 180/79 the vehicle to provide for propersteering of the vehi- FOREIGN PATENTS OR APPLICATIONS cle regardless OfWhlCll end of the vehicle 1s the front end 1n the direction of movementof the vehicle. 743,825 1/1933 France lO4/247 5 Claims, 8 DrawingFigures 84 62 84a 3 l" l, .3 o 38 42 o 420. 380 32a 75a ll" l|"1 77 234T 48 254 u l/nul 48a 34 3 88a 3 75 252 28 2| 46 I a 7 u I I y 444 25623 440 I I: 9 L. T 203 I s Hlh E 9 d (a. n ,IH u lit... l X890 t 53 i i*1 v 251 QZZ-J: O a

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74 34 22 340 ..i- 50 ill' Z 8B 3 62 l?9 I eat: 83 38 380 I" o gi 1 |i||||ll1- F li l 8| Blu Patented Jan. 7, 1975 4 Sheets-Sheet 2 PatentedJan. 7, 1 975 4 Sheets-Sheet 5 EEEEEEM E? Z: 2: mm

Patented Jan. 7, 1975 3,858,523

4 Sheets-Sheet 4 VEHICLE STEERING MECHANISM This invention relates tovehicles steering mechanisms and to motion translating devices.

Vehicles which are provided with pairs of wheels at their opposite ends,with each pair being controlled by a separate steering mechanism havinga transversely movable steering member, must have motion translatingmeans for causing the pair of wheels to turn in one direction when thesteering member is moved transversely in a given direction when the pairof wheels is at the front end of the vehicle in the direction ofmovement of the vehicle and to turn the wheels in the opposite directionupon the movement of the steering member in such given directionrelative to the vehicle when the direction of movement of the vehicle isreversed so that the pair of wheels which were formerly at the front endof the vehicle become the rear wheels and vice versa.

Accordingly, it isan object of this invention to provide a new andimproved vehicle steering mechanism having a motion translating deviceconnected between a transversely movable main steering member of themechanism and the pair of wheels it controls for causing the vehicle toturn in a selected one of two opposite directions on movement of thesteering member in a given direction.

Another object is to provide a vehicle steering mechanism wherein themotion translating device is provided in the steering mechanism linkageconnecting the steering member to the wheels.

Still another object is to provide a vehicle steering mechanism, of thetype described, wherein the motion translating device has a bodyconnected to the vehicle axle for pivotal movement about a first axisand input and output members pivotally connected to the body, with oneof the members being pivotal relative to the body about a second axispositionable in a first position located between the first axis and thethird axis of pivotal movement of the other member relative to the bodyso that the output member is moved in the same direction as the inputmember when a force applied to the input member causes the body to pivotabout the first axis, and a second position wherein the first axis isdisposed between the second and third axes so that the output member ismoved in a direction opposite to the direction of movement of the inputmember when a force applied to the input member causes the body to pivotabout the first axis.

An important object of the invention is to provide a motion translatingdevice for selectively changing the direction of movement of an outputmember relative to the direction of movement of an input member.

Another object is to provide a motion translating device having a bodypivotally connectable to a base structure for movement about a firstaxis, an input member pivotally connected to the body for pivotalmovement relative thereto about a second axis spaced from the firstaxis, and an output member pivotally connected to the body for movementabout a third axis selectively positionable in a first position whereinthe third axis is located between the first and second axes, so thatwhen the body is pivoted about the first axis by a force applied to theinput member the output member is moved in the same direction as theinput member, and a second position wherein the first axis is disposedbetween the second and third axes whereby when the body is pivoted aboutthe first axis by a force applied to the input member, the output memberis moved in a direction opposite to the direction of movement of theinput member.

Still another object is to provide a motion translating device, of thetype described, having an adjusting mechanism connecting the outputmember to the body for moving the axis of pivotal connection of theoutput member relative to the body selectively between the first andsecond positions.

A further object of the invention is to provide a motion translatingdevice, of the type described, wherein the motion translating device hasa lock means for locking the adjusting mechanism when the axis ofpivotal connection of the output member is in either of the first andsecond positions.

A still further object is to provide a motion translating device havingindicator means for indicating if the axis of pivotal connection of theoutput member is in either of its two selected operative positions.

Other objects and advantages will beapparent from the specification andclaims and from the accompanying drawing illustrative of the invention.

In the drawing:

FIG. 1 is a top view, with some parts broken away, of the frame of avehicle whose wheel steering mechanisms are provided with motiontranslating devices embodying the invention;

FIG. 2 is a side view, with some parts broken away, of the vehicleillustrated in FIG. 1;

FIG. 3 is an end view, with some parts broken away,

' of the vehicle illustrated in FIG. 2;

FIG. 4 is a plan view, with some parts broken away and some shown insection 1, of a motion translating device embodying the inven'tion;

FIG. 5 is a side view of the device illustrated in FIG. 4; and,

FIGS. 5, 6, 7' and 8 are plan views of selected elements of the motiontranslating device.

Referring now to the drawings, the vehicle 20, which is provided with amotion translating devices embodying the invention, includes a mainframe 21 comprising a pair of parallel longitudinal side members 22 and23 which are connected by a plurality of transverse members 24. The sidemembers 22 and 23 at one end have dependent legs 25 and 26 provided attheir lower ends with extensions 27 and 28 which are rigidly secured, inany suitable manner, to an axle 29. The axle at its opposite ends isprovided with substantially vertical king pins 31 and 32 on whosehorizontal spindles are rotatably mounted the usual hubs 34 to whichthe-wheel 35 may be secured. The wheels are of course provided withresilient tires 38. The wheels 41 and 42, each formed of a wheel diskand a tire, are caused to turn simultaneously about the vertical axes oftheir king pins 31 and 32, respectively, by a tie rod 44 whose oppositeends are pivotally connected, as at 45 and 46, to the arms 47 and 48rigidly connected in the usual manner to the king pins 31 and 32,respectively, so as to comprise the well known Ackerman Steering Linkagewhich minimizes tire wear.

The king pin 31 has an arm 50 rigidly secured to its top end. One end ofa link 51 is pivotally connected, as at 52, to the king pin arm 50 andits other end is pivotally connected, as at 53, to a lever arm 54rotatably mounted, by suitable bearing means, on a vertical shaft 55rigidly mounted on the forward end of a draw bar 56 which extends froman adjacent transverse member 24 of the frame 21. The towing bar of atowing vehicle is rigidly securable to the lever arm 54 which isrotatable on the shaft 55 with the towing vehicle; therefore, the leverarm 54 will rotate with the towing vehicle tow bar as the towing vehicleturns relative to the vehicle and will cause the linkage comprising thelever arm 54, the link 51 and the arm to cause the king pin 31 to rotatein the direction of turning movement of the towing vehicle. Since theking pins 31 and 32 are connected by the rod 44, the two wheels of thevehicle will then be turned about the axes of their king pins in thesame direction as the turning movement of the towing vehicle.

The vehicle is specially adapted to be moved in a predetermined pathover a roadway which has a planar road surface 61 and side walls 62 and63. The vehicle may be driven in any suitable manner over the roadway.For example, one or more of the wheels 41, 42, 41a and 42a may be drivenby an electric motor or the vehicle may have mounted thereon theprimaries of two linear induction motors along its sides in which casethe secondaries of the motors would be mounted along the sides of theroadway 61.

During movement of the vehicle over the roadway, thewheels 41 and42 aresteered by a steering mechanism which includes a transverse follower bar71 which hastwo arms 72 and 73 pivotally connected, as by shafts 74 and75, to the other ends of brackets 76 and 77 whose inner ends are rigidlysecured by any suitable means to the axle 29.

At its opposite ends, the follower bar is provided with wheel assemblies81 and 82 each of whichcomprises a bracket 83 bolted to the end of thefollower bar and a plurality of wheels 84 mounted on the barfor'rotation about vertical axes. The wheels of the assembly 81 areengageable with the roadway wall 62 while the wheels of the assembly 82are engageable with the roadway wall 63.

It will be apparent that the follower bar will move transverselyrelative to the frame of the vehicle in one direction or the other aseither one set or the other of the guide wheels engages its associatedroadway wall if the vehicle tends to move laterally toward such wall orif such wall curves, as at locations of changes of direction of theroadway.

The follower bar 71 of the steering mechanism 70 is connected to asteering arm 88 of the king pin 31 by a motion translating device T anda link 89.

The motion translating device T, FIGS. 5 and 6, for selectively causingits output member 90 to move either in the same direction or in adirection opposite to that of its input member 91, includes a body 92formed of two parallel plates 93 and 94 which are connected and held inspaced relation by a wall strip 95, welded thereto, which extends fromthe location A, to the location B and at its lower portion is providedwith a notch 96.

Two pairs of cam bars- 97 and 98 are secured to the inner side of thebody plate 93 by bolts 101 and 102, respectively, which extend throughsuitable apertures in the plate 93 into suitable threaded bores of thecam bars.

The pairs of cam bars 97 and 98 extend convergently outwardly from themiddle of the body in opposite directions.

The bottom plate 94 similarly has two pairs of cam bars 103 and 104secured thereto by bolts 105 and 106,

respectively. The cam bars 103 are in alignment with the cam bars 97while the cam bars 104 are in alignment with the cam bars 98.-

The output member or rod 90 of the motion translating device extendslaterally outwardly of the body through the space between the pairs ofcam bars 97 and 103 and the bars 98 and 104 at the right side of thebody, FIG. 4. The inner end portion 111 of the output rod is flattenedand extends into the slot 112 defined by the inner spaced end portions113 and 114 ofa clevis 115. The portion l11is pivotally connected to theclevis by a shaft 118 which extends through aligned apertures'in theclevis portions 113 and 114 and the portion 111. The shaft has oppositeend portions extending outwardly of the clevis on which are rotatablymounted cam bar engaging'rollers 121 and 122 which are secured rotatablyon the shaft 118 by suitable retainers 123.

The roller'121 is engageable with the inner surface of the pairs of cambars 97 and 98 while the roller 122 is engageable with the innersurfaces of the pairs of cam bars 103 and 104.

A screw 125 has one end portion telescoped in the socket 126 of theclevis and held rigidly therein by a bolt 127 which extends throughaligned apertures in the screw and the clevis socket.

The screw extends into a tubular member 130 which has a nut or threadedmember 131, rigidly secured in the enlarged end portion 132 thereof,which is in threaded engagement with the screw.

The tubular memberis secured to the body 92 by a mounting assembly 133which permits rotational movement of the tubular body, while preventingits longitudinal movement, relative to the body 92.

The mounting assembly 133 includes a bearing block 135, FIGS. 4 and 6which is positioned between the plates 93 and 94 and rigidly securedthereto in any suitable manner, as by welding. The bearing block has adownwardly opening recess 135a in which is disposed a bearing 136 whichhas an arcuate or spherical seat for engaging a ball section member 137disposed about the tubular member 130. The mounting assembly alsoincludes a retainer 138, FIGS. 4 and 8, rigidly secured to the bearingblock by bolts 139 which extend through suitable apertures 140 in thebearing block into threaded bores 141 of the retainer.

The tubular member 130 is provided on its other head with a hexagonalnut 144 so that the tubular mem ber may be rotated by a suitable tool,such as a wrench, not shown.

A locking assembly is mounted on the tubular member 130, between theball section member 137 and a nut 151 threaded on the threaded enlargedsection 152 of the tubular member, and includes a spacer sleeve 153, aretainerring 154, a lock ring 155, having external longitudinal slots156, held against rotation by a tongue 157 disposed in aligned externaland internal longitudinal recesses or slots 158 and 159 of the tubularmember and the lock ring, respectively, a split retainer ring 160 whichhas a slot 161, and a retainer ring 162.

A bracket 164 (FIGS. 4, 5 and 7) has a circular portion 165 whichextends about the lock ring between the retainer rings 154 and 160 andspaced parallel arms 167 and 168. The arms 167 and 168 extend outwardlythrough the slot 169 provided by the legs 170 and 171 of the retainermember 138 and the bracket 164 is therefore held against rotation aboutthe tubular member due to the engagement of its arms with the retainermember legs.

A latch member 174 is pivotally mounted to and between the arms 167 and168 by a bolt 175 which extends through aligned apertures in the outerends of the arms and the upper outer end of a planar member 176 of thelatch member. The planar member has a tooth portion 177 extendingangularly from its end which is adapted to move through the slot 161 ofthe retainer ring 160 and a selected slot 156 of the lock ring as thelatch member is pivoted about the axis of the bolt 175. The latch memberis biased in a clockwise direction, FIG. 4, toward locking position,wherein its tooth 177 is in a slot 156 of the lock ring thus preventingrotation of the tubular member, by a spring 180 whose hooked end 181extends through an aperture in a lug 182 of the planar member 176. Theother hooked end 184 of the spring is hooked over a pin 185 secured to apair of bars 186 which extend through facing slots 187 of the arms andare secured thereto in any suitable manner, as by welding.

The latch member 174 may include a cover 190 hav' ing a planar section191 secured to the planar member 176 by welding, an end section 192 andside flanges 193 and 194. It will be apparent that when the latch memberis in its locking position, the hexagonal nut 144 is disposed betweenthe side flanges 193 and 194.

The body 92 of the motion translating device T is pivotally secured tothe axle 29 by a pair of vertically spaced and aligned angle brackets200 whose legs 201 and 202 are secured rigidly to brackets 203 and 204which extend from the axle. The body 92 is disposed between the pair ofbrackets 200 and is secured thereto by shafts 206 (FIG. 4) which extendthrough bores 207 of a pair of mounting lugs 208 into suitable aperturesof the brackets. The mounting lugs have legs 209 which are welded to theplates 93 and 94 and strap portions 210 which overlap the brackets 200.The axis of the shafts 106 is the axis y of pivotal movement of the body92.

The input member 91 of the motion translating device is rigid with thefollower bar and extends into the slot 216 of the bearing block and ispivotally secured thereto by a shaft 217 which extends through suitablealigned apertures in the input member 91 and the bearing block.

The output member 90 is rigidly connected to the link 89, its outer endportion 218 being threadedin a suitable threaded bore of the link 89. Alock nut 219 is on the threaded portion to lock the link in selectedposition.

It will now be apparent that the motion translating device include thebody 92 which is mounted for pivotal movement about a first axis y, theaxis of the shafts 106, and that the output and input members 90 and 91are pivotally connected to the body for pivotal movement about the axesx and 2, respectively. It will also be apparent that when the axisy islocated between the axes x and z, the output member will be moved in adirection opposite to the direction of movement of the input member 91and that when the axis x is moved to a position between the axes y andz, the output member 90 will move in the same direction as the inputmember 91 as the body is pivoted about the axis y due to a forcesupplied thereto by the input member 91.

It will now be apparent that if the vehicle is moving to the left asseen in FIG. 1, the wheels 41 and 42 are at the front end of the vehiclein the direction of movement thereof and must turn in a clockwisedirection about the axes of their king pins 31 and 32 if the vehiclemust be turned to the left, as when the vehicle tends to move toward theside wall 62 and the vehicle frame is moved laterally toward the sidewall and relative to the follower bar due to the engagement of the wheelassembly 82 and the side wall 62 or the roadway curves to the left andthe follower bar is moved transversely to the left relative to thevehicle frame. In this case the motion translating device T is placed inthe position illustrated in FIGS. 4 and 5 of the drawing wherein the camrollers 21 and 22 are in engagement with the cam bars 98 and 104,respectively and in full lines in FIG. 1.

The link 89 and the output rod are now in the full line positionsillustrated in FIG. 1 so that the axis of pivotal connection of theoutput rod with the clevis is located between the location of pivotalconnections of the body 92 with the follower bar and the brackets 200.As a result, the output rod, and therefore the link, will move laterallyin the same direction as the follower bar and the rod or input member 91when the follower bar is moved laterally.

If the vehicle is moving to the right so that the wheels 41 and 42 arenow at the rear of the vehicle, if the vehicle now tends to movelaterally on the roadway or must change directions of movement at curvedportions of the roadway, it is necessary that the direction of lateralmovement of the output member and link 89 be opposite to that of thefollower bar and the input member 91. The tubular member is thereforerotated until the clevis is at its other extreme position, illustratedin broken lines in FIG. 4, with the cam rollers 21 and 22 in engagementwith the cam bars 97 and 103. The output rod 90 and the link 89 are nowin the position illustrated in broken line in FIG. 1 with the axis y ofpivotal connection of the body 92 to the axle being disposed between theaxis x of pivotal connection of the clevis and output rod with the body92 and the axis 2 of pivotal connection of the body 92 with the inputmember 91. As a result, if the vehicle is now moving to the right, FIG.1, and the vehicle tends to move laterally toward the side wall 62, thevehicle frame due to the engagement of the wheel assembly 82 with theside wall 62, will move toward the side wall and relative to thefollower bar, and the wheels will be pivoted in clockwise manner aboutthe vertical axes of their king pins.

The wheel 41a and 42a at the other end of the vehicle frame areconnected to one another, to the frame and the steering mechanism in thesame manner as are connected the wheels 41 and 42 and, accordingly thevarious elements of the means associated with the wheels 41a and 42ahave been provided with the same reference characters, to which thesubscript a has been added, as the various elements of the meansassociated with the wheels 41 and 42.

It is desirable, when the vehicle is being towed, that the pair ofwheels turn, but in the opposite direction, when the front wheels turnto facilitate turning movement of the vehicle and minimize tire wear. Alinkage 250 which connects the king pins of the wheels 42 and 42a isprovided for this purpose.

The linkage 250 includes a link 251 pivotally connected at one end tothe arm 252 of the king pin 32 and at its other end to one end of areversing lever 253 which is pivotally connected as at 254 to the frameby means of a bracket 255 secured to the side frame. The other end ofthe reversing lever is pivotally connected to one end of an overloaddevice 256. It will be apparent that since the axis of pivotal movementof the reversing lever is between the axes of pivotal connections of thelever with the link 251 and the overload device, the overload devicewill be moved to th left when the link 251 is moved to the right andvice versa. The other end of the overload device is connected to the arm252a of the king pin 32a by support levers 257, 258, and 259 and thelinks 260, 261 and 263 which extend between and are pivotally connectedto the support levers. The support levers are pivotally secured to theframe by suitable brackets 264 and shaft 265.

The overload device, which is not per se a part of the claimedinvention, permits movement of the link 251 relative to the link 260 inthe event that the force tending to prevent turning of the one pair ofwheels as the other pair of wheels is turned exceeds a predeterminedvalue. I

In certain installations, it is necessary that the axis of pivotalconnection of the output member 90 of the motion translating device beindicated, as to the controller of the operation of the vehicle, or theoperation of the vehicle be prevented if the axis x is not in theproperrelation relative to the axes y and z. To provide a position or controlsignal, a pair of micro-switches 271 and 272 may be secured to the bodyplate 93 by any suitable means, such as bolts 273 and spacers 274. Theoperator arms or levers 275 of the switches 271 and 272 are engageableby the roller 121-and either close or open an indicator or controlcircuit only when the clevis 115 is in either of its extreme positionsrelative to the body wherein it is held rigid due to engagement of itsrollers 121 and 122 either with the pairs of cam bars 98 and 104,respectively, or the pairs of cam bars 97 and 103 respectively.

It will be apparent that the operative conditions of the motiontranslating devices T and Ta must be ascertained before motive power isapplied thereto so that each pair of wheels will turn as required toprevent damage when its associated follower bar 71 and 71a,respectively, is moved transversely relative to the vehicle frame asdueto the engagement of the wheels of their follower bar wheelassemblies with a side wall of a roadway or the turning of an end of theframe relative to the wheels at that end.

If the vehicle is moving to the left as seen in FIG. 1, the outputmembers 91 and 91a of the motion translating devices T and Ta must be inthe positions illustrated in full lines. If the vehicle is to move tothe right, the output members 91 and 91a must be moved to the positionsillustrated in broken lines in FIG. 1.

During movement of the vehicle over aroadway 60, the linkage 250 will,of course, exert a force resisting turning movement of the wheels of therear pair of wheels 41a and 420 relative to the roadway about thevertical axes of their king pins as the front wheels 41 and 42 turn in acounterclockwise manner about the vertical axes of their king pins sincethe rear wheels are still travelling over a straight portion of theroadway. Such turning movement of the rear wheels will also be resistedby the engagement of the wheel assembly 83a with the side wall 62 of theroadway. The overload devic 256 will yield when the force applied to thelinkage 250, compression or tension, at the overload device, exceeds apredetermined limit and permit the lever 257 to remain substantiallymotionless as its rod 280 is allowed to retract into or extend from itshousing 281.

If the vehicle is to be towed by a force applied to the tow shaft 55over an open road, so that the turning movements of the vehicle arecontrolled by the turning moveemnt imparted to the lever arms 54 or 54ato which the tow bar of the towing vehicle is rigidly secured, theoperative conditions of the two motion translating devices is of nomovement since the linkage 250 will, as was explained above, cause therear wheels to turn in directions reverse to those of the front wheelsrelative to the vehicle as the front wheels are turned by the towingvehicle. The overload device again will protect the steering mechanismfrom damage as, for example, if the rear wheels are in ruts and cannotturn.

The generally parallelogram configuration provided by theconvergent-divergent plan configuration of the cam bar sets 98, 104 and97, 103 provides the additional, important advantage that thetranslating device T provides a mid position of the inner end portion111 of theoutput member wherein a degree of moveemnt of the body 92about the pivotal axis of pivot shaft 206 is permitted without effectingany axial movement of output member 90. Conversely, in the mid positionthe output member 90 is free to move axially within device T for alimited degree without effecting pivotal movement of body 92, because ofthe provision of the mounting assembly 133 with its ball section member137 which permits the input member 91, including tubular member 130, topivot about the center of ball member 137 (clockwise andcounter-clockwise as viewed in FIG. 4); this pivotal movement thuspermits the output rod 90 to translate, axially, with respect to thebody 92 and within the cam bars 98, 104, 97, 103 without moving body 92.

This advantageous feature permits a greater variety of applications forthe translating device T. For example, an important advantage in thepresent embodiment is that when it is desired to tow the vehicle, it ispossible to disconnect the follower bar 71 from the output member 90 forpermitting turning movement of the wheels, connected to the outputmember 90, without movement of the follower bar 71, connected to thebody 92. This is advantageous when it is desired not to move thefollower bars 71, 71a during towing of the vehicle off the guideway. Inthe vehicle of the present example, the follower bars 71, 71a arerestricted in transverse movement because of other designconsiderations. Moreover, it is not desirable that the follower bars 71,71a project excessively outwardly from the vehicle during off-guidewayoperation because they may be exposed to damageby collision withadjacent structures.

It will now be seen'that a new and improved steering means for towed orself propelled vehicles has been illustrated and described with permitsthe vehicle to move in either longitudinal direction with the turningmovements of the pairs of front and rear wheels being controlled byseparate steering mechanisms each including a motion translating deviceinterposed between the king pins of its associated pair of wheels and asteering or control member, such as the follower bars, for selectivelyreversing the direction of towing movement of the wheels in relation togiven movement of the control member relative to the vehicle.

It will also be seen that a new and improved motion translating devicehas been illustrated and described which is of simple structure having abody pivotally securable to a fixed structure, an input member pivotallysecured to the body at a fixed location, and an output member which issecured to the body by means which permit its axis of pivotal connectionto the body to be adjusted to permit the output member to be movedeither in the same or opposite direction as the input member by the bodyas the body is pivotally moved by a force applied to the body.

While only one embodiment of the invention, together with severalmodifications thereof, has been described in detail herein and shown inthe accompanying drawing, it will be evident that various furthermodifications are possible in the arrangement and construe tion of itscomponents without departing from the scope of the invention.

What is claimed is:

l. A vehicle steering mechanism for a pair of transversely alignedvehicle supporting wheels turnable about substantially vertical axes andconnected by a transversely extending axle, said mechanism including:

a steering control member mounted on said vehicle for movement relativethereto;

a linkage connecting said control member to said wheels for causing saidwheels to turn about said vertical axes upon relative movement betweensaid control member and the vehicle,

said linkage including a motion translating device having a body mountedon the axle for pivotal movement about a first axis,

an input member connected to said control member and movable therewith,

said input member being connected to said body for pivotal movementabout a second axis;

an output member pivotal about a third axis relative to said body andconnected to said wheels; and

adjustable connecting means connecting said output member to said bodyfor selectively varying the position of said output member relative tosaid body to cause said third axis to be positionable between said firstand second axes wherein said output member is in a first positionrelative to said body and to cause said first axis to be located betweensaid second and third axes wherein said output member is in a secondposition relative to said body whereby said output member is moved inthe same direction as the input member when the output member is in saidfirst position and in a direction opposite the direction of movement ofsaid input member when the output member is in said second position tocause the wheels to turn in one direction upon a movement of the controlmember in a given direction when the output member is in said firstposition and to turn in a direction opposite said one direction when theoutput member is in said second position.

2. The mechanism of claim 1, wherein said control member is movabletransversely relative to said vehicle,

said wheels being mounted on substantially vertical king pins and atleast one of said pins has a steering arm extending perpendicularlytherefrom,

said output member being connected to said steering arm.

3. The mechanism of claim 2, wherein said connecting means comprises anelongated member adjustably mounted on said body and having one endpositionable in one position between said first and second axes andanother position wherein said first axis is between said second andthird axes, said output member having one end pivotally connected tosaid one end of said elongate member.

4. The mechanism of claim 3, wherein said motion translating deviceincludes lock means for locking said elongate member against movementrelative to said body.

5. The mechanism of claim 4, wherein said motion translating deviceincludes a pair of spaced electric switch means one of which is operatedby said connecting means when said elongate member is in said oneposition and the other of which is operated by said connecting meanswhen said elongate member is in said another position.

1. A vehicle steering mechanism for a pair of transversely alignedvehicle supporting wheels turnable about substantially vertical axes andconnected by a transversely extending axle, said mechanism including: asteering control member mounted on said vehicle for movement relativethereto; a linkage connecting said control member to said wheels forcausing said wheels to turn about said vertical axes upon relativemovement between said control member and the vehicle, said linkageincluding a motion translating device having a body mounted on the axlefor pivotal movement about a first axis, an input member connected tosaid control member and movable therewith, said input member beingconnected to said body for pivotal movement about a second axis; anoutput member pivotal about a third axis relative to said body andconnected to said wheels; and adjustable connecting means connectingsaid output member to said body for selectively varying the position ofsaid output member relative to said body to cause said third axis to bepositionable between said first and second axes wherein said outputmember is in a first position relative to said body and to cause saidfirst axis to be located between said second and third axes wherein saidoutput member is in a second position relative to said body whereby saidoutput member is moved in the same direction as the input member whenthe output member is in said first position and in a direction oppositethe direction of movement of said input member when the output member isin said second position to cause the wheels to turn in one directionupon a movement of the control member in a given direction when theoutput member is in said first position and to turn in a directionopposite said one direction when the output member is in said secondposition.
 2. The mechanism of claim 1, wherein said control member ismovable transversely relative to said vehicle, said wheels being mountedon substantially vertical king pins and at least one of said pins has asteering arm extending perpendicularly therefrom, said output memberbeing connected to said steering arm.
 3. The mechanism of claim 2,wherein said connecting means comprises an elongated member adjustablymounted on said body and having one end positionaBle in one positionbetween said first and second axes and another position wherein saidfirst axis is between said second and third axes, said output memberhaving one end pivotally connected to said one end of said elongatemember.
 4. The mechanism of claim 3, wherein said motion translatingdevice includes lock means for locking said elongate member againstmovement relative to said body.
 5. The mechanism of claim 4, whereinsaid motion translating device includes a pair of spaced electric switchmeans one of which is operated by said connecting means when saidelongate member is in said one position and the other of which isoperated by said connecting means when said elongate member is in saidanother position.